In the industrial fields of, for example, fabricating a microscopic structure (e.g., a micromachine, a magneto-resist head, and the like) as well as microelectronics, it is required to provide a number of circuits more than expected in the provided chip size by decreasing the pattern size. Effective lithographic techniques are essential to achieve a reduction in the size of structural shapes. Lithography affects on fabricating a microscopic structure in the views of directly imagining a pattern on a predetermined substrate and of providing a mask typically used for the imagification.
A typical lithographic process involves the following processes. First, a radiation-sensitive resist is exposed in patternwise method to form a patterned resist layer. Subsequently, the exposed resist layer is developed using a developing solution. Then, the substance present in openings of the patterned resist layer is etched to transfer a pattern to an underlying material. After completion of the transfer, remaining portions of the resist layer are removed.
However, in some lithographic imagification processes, the used resist does not provide an enough resistance for the subsequent etching step so that a predetermined pattern is not effectively transferred to the layer on the back surface. Accordingly, for example, when requiring an ultra-thin resist layer, the underlayer, called a hardmask layer, is used as an intermediate layer between the resist layer and the underlying material that may be transferred from the patterned resist to be patterned in the case that the underlying material to be etched is thick; in the case of requiring a considerable etching depth; and/or in the case of requiring a certain etchant for the predetermined underlying material.
The hardmask layer receives a pattern from a patterned resist layer, and should endure an etching process required for transferring a pattern to an underlying material.
The hardmask layer is required for a lithography technology using a composition for a hardmask having etching selectivity and an enough resistance against the multietching and also being capable of minimizing the reflectivity between resist and underlying layer. A pattern using such a hardmask composition may have improved optical properties.